[Today is a two-post day at Football Perspective. Check here for my week 2 power rankings, while Neil provides an innovative look at the biggest comebacks of the last 35 years in this post. — Chase
In my last post, I introduced a method of estimating the home team’s pre-game win probability in Excel using the Vegas spread:
p(W) = (1-NORMDIST(0.5,-(home_line),13.86,TRUE)) + 0.5*(NORMDIST(0.5,-(home_line),13.86,TRUE)-NORMDIST(-0.5,-(home_line),13.86,TRUE))
The Comeback ranks as the 2nd most impressive comeback after two quarters, but only 20th overall.
With a small twist, we can also apply this formula within games, to the line-score data for every quarter. Within a game, the home team’s probability becomes:
p(W) = (1-NORMDIST(away_margin+0.5,-home_line*(minleft/60),13.86/SQRT(60/minleft),TRUE))+0.5*(NORMDIST(away_margin+0.5,-home_line*(minleft/60),13.86/SQRT(60/minleft),TRUE)-NORMDIST(away_margin-0.5,-home_line*(minleft/60),13.86/SQRT(60/minleft),TRUE))
This is the same equation as before, but we’re adding in Home_Margin (home team pts minus road team pts for the game, through the end of the quarter in question), reducing the effect of the home Vegas line linearly based on how much time remains in the game, and changing the standard deviation of scoring margin to become:
Stdev = 13.86 / sqrt(60 / n)
where n = the number of minutes remaining in the game.
These changes will help us estimate a team’s chances of winning at the end of each quarter. For instance, Monday night’s game — where the Falcons were a 3-point home favorite over the Broncos — goes from:
| Team | 1st | 2nd | 3rd | 4th | Total |
|---|---|---|---|---|---|
| Atlanta | 10 | 10 | 7 | 0 | 27 |
| Denver | 0 | 7 | 0 | 14 | 21 |
To this:
| Team | Pregame | After 1st | At Half | After 3rd | Final |
|---|---|---|---|---|---|
| Atlanta | 58.6% | 84.6% | 93.0% | 99.9% | 100.0% |
| Denver | 41.4% | 15.4% | 7.0% | 0.1% | 0.0% |
If you made it through all that, my hat’s off to you — and now let’s look at the real reason you’re here, the list of the biggest quarter-by-quarter comebacks since 1978. In each case, the columns represent the percentage likelihood of winning for the home team:
| Rank | Game | Pregame | After 1st | At Half | After 3rd | After 4th | Final | Comeback |
|---|---|---|---|---|---|---|---|---|
| 1 | 12/1/1985 min 28 @ phi (-6.5) 23 | 68.03% | 89.22% | 99.11% | 99.98% | 0.00% | 0.00% | 0.02% |
| 2 | 11/8/1987 tam 28 @ crd (-2.5) 31 | 57.15% | 33.48% | 16.02% | 0.02% | 100.00% | 100.00% | 0.02% |
| 3 | 10/23/2000 mia 37 @ nyj (-3) 40 | 58.56% | 10.98% | 6.98% | 0.07% | 50.00% | 100.00% | 0.07% |
| 4 | 10/6/2003 clt 38 @ tam (-4.5) 35 | 62.72% | 92.60% | 99.11% | 99.93% | 50.00% | 0.00% | 0.07% |
| 5 | 11/26/2006 nyg 21 @ oti (3.5) 24 | 40.04% | 21.15% | 1.02% | 0.08% | 100.00% | 100.00% | 0.08% |
| 6 | 9/12/1999 dal 41 @ was (-2.5) 35 | 57.15% | 42.98% | 51.02% | 99.91% | 50.00% | 0.00% | 0.09% |
| 7 | 10/4/1992 was 24 @ crd (10) 27 | 23.54% | 3.68% | 1.25% | 0.16% | 100.00% | 100.00% | 0.16% |
| 8 | 10/21/1984 nor 27 @ dal (-6) 30 | 66.74% | 73.38% | 20.75% | 0.25% | 50.00% | 100.00% | 0.25% |
| 9 | 9/26/1988 rai 30 @ den (-6.5) 27 | 68.03% | 83.85% | 99.73% | 95.29% | 50.00% | 0.00% | 0.27% |
| 10 | 12/4/2005 buf 23 @ mia (-3) 24 | 58.56% | 5.93% | 4.63% | 0.28% | 100.00% | 100.00% | 0.28% |
| 11 | 10/4/1992 chi 20 @ min (-4) 21 | 61.35% | 50.00% | 13.12% | 0.31% | 100.00% | 100.00% | 0.31% |
| 12 | 12/11/1993 sfo 24 @ atl (8) 27 | 28.20% | 30.87% | 7.68% | 0.31% | 100.00% | 100.00% | 0.31% |
| 13 | 12/5/2004 cin 27 @ rav (-6.5) 26 | 68.03% | 74.39% | 73.79% | 99.63% | 0.00% | 0.00% | 0.37% |
| 14 | 10/8/1995 clt 27 @ mia (-10) 24 | 76.46% | 96.32% | 99.60% | 99.12% | 50.00% | 0.00% | 0.40% |
| 15 | 9/17/2006 nyg 30 @ phi (-3) 24 | 58.56% | 57.43% | 87.94% | 99.47% | 50.00% | 0.00% | 0.53% |
| 16 | 10/12/2003 kan 40 @ gnb (-2.5) 34 | 57.15% | 77.00% | 79.97% | 99.44% | 50.00% | 0.00% | 0.56% |
| 17 | 12/27/2009 tam 20 @ nor (-14) 17 | 84.36% | 97.93% | 98.38% | 99.41% | 50.00% | 0.00% | 0.59% |
| 18 | 12/7/1980 nor 35 @ sfo (-7) 38 | 69.31% | 23.32% | 0.63% | 3.89% | 50.00% | 100.00% | 0.63% |
| 19 | 12/6/1992 ram 31 @ tam (-1) 27 | 52.87% | 71.29% | 99.37% | 68.00% | 0.00% | 0.00% | 0.63% |
| 20 | 1/3/1993 oti 38 @ buf (-2) 41 | 55.73% | 41.76% | 0.72% | 30.72% | 50.00% | 100.00% | 0.72% |
| 21 | 10/28/2001 nor 34 @ ram (-12) 31 | 80.65% | 95.20% | 99.28% | 28.24% | 0.00% | 0.00% | 0.72% |
| 22 | 12/11/1983 clt 19 @ den (-8.5) 21 | 73.00% | 61.06% | 11.56% | 0.76% | 100.00% | 100.00% | 0.76% |
| 23 | 12/21/1996 nwe 23 @ nyg (8.5) 22 | 27.00% | 35.79% | 96.48% | 99.24% | 0.00% | 0.00% | 0.76% |
| 24 | 9/12/1982 ram 23 @ gnb (1) 35 | 47.13% | 18.54% | 0.83% | 9.15% | 100.00% | 100.00% | 0.83% |
| 25 | 12/24/1995 min 24 @ cin (5) 27 | 35.92% | 37.75% | 0.83% | 11.75% | 100.00% | 100.00% | 0.83% |
| 26 | 11/10/1996 crd 37 @ was (-10.5) 34 | 77.55% | 74.39% | 70.37% | 99.16% | 50.00% | 0.00% | 0.84% |
| 27 | 10/4/1998 det 27 @ chi (-2) 31 | 55.73% | 23.96% | 54.06% | 0.88% | 100.00% | 100.00% | 0.88% |
| 28 | 11/4/1990 was 41 @ det (3) 38 | 41.44% | 42.57% | 89.86% | 99.03% | 50.00% | 0.00% | 0.97% |
| 29 | 8/31/1997 crd 21 @ cin (-7.5) 24 | 70.57% | 45.44% | 23.00% | 1.01% | 100.00% | 100.00% | 1.01% |
| 30 | 10/25/1987 buf 34 @ mia (-9.5) 31 | 75.33% | 96.07% | 98.98% | 82.06% | 50.00% | 0.00% | 1.02% |
| 31 | 9/13/1981 atl 31 @ gnb (4) 17 | 38.65% | 63.04% | 88.93% | 98.94% | 0.00% | 0.00% | 1.06% |
| 32 | 11/24/1996 jax 28 @ rav (-4) 25 | 61.35% | 79.74% | 79.25% | 98.94% | 50.00% | 0.00% | 1.06% |
| 33 | 10/10/2004 ram 33 @ sea (-8) 27 | 71.80% | 86.04% | 98.38% | 98.94% | 50.00% | 0.00% | 1.06% |
| 34 | 12/19/2010 phi 38 @ nyg (-3) 31 | 58.56% | 77.93% | 98.91% | 98.31% | 0.00% | 0.00% | 1.09% |
| 35 | 11/18/1984 mia 28 @ sdg (7) 34 | 30.69% | 55.79% | 14.23% | 1.17% | 50.00% | 100.00% | 1.17% |
| 36 | 10/2/2011 sfo 24 @ phi (-10) 23 | 76.46% | 88.63% | 98.75% | 88.94% | 0.00% | 0.00% | 1.25% |
| 37 | 11/6/1988 sfo 23 @ crd (-3) 24 | 58.56% | 47.51% | 6.98% | 1.41% | 100.00% | 100.00% | 1.41% |
| 38 | 1/5/2003 nyg 38 @ sfo (-3) 39 | 58.56% | 57.43% | 10.14% | 1.41% | 100.00% | 100.00% | 1.41% |
| 39 | 10/31/1993 det 30 @ min (-4) 27 | 61.35% | 59.86% | 72.95% | 98.46% | 0.00% | 0.00% | 1.54% |
| 40 | 12/30/2001 pit 23 @ cin (8) 26 | 28.20% | 4.80% | 13.12% | 1.54% | 50.00% | 100.00% | 1.54% |
| 41 | 10/23/1983 atl 27 @ nyj (-3.5) 21 | 59.96% | 58.65% | 81.37% | 98.39% | 0.00% | 0.00% | 1.61% |
| 42 | 11/28/1999 kan 37 @ rai (-3.5) 34 | 59.96% | 68.02% | 68.58% | 98.39% | 0.00% | 0.00% | 1.61% |
| 43 | 12/3/1979 rai 42 @ nor (-3) 35 | 58.56% | 34.63% | 94.29% | 98.31% | 0.00% | 0.00% | 1.69% |
| 44 | 11/27/1980 chi 23 @ det (-3) 17 | 58.56% | 66.89% | 80.68% | 98.31% | 50.00% | 0.00% | 1.69% |
| 45 | 11/21/1983 nyj 31 @ nor (-3) 28 | 58.56% | 77.93% | 56.07% | 98.31% | 0.00% | 0.00% | 1.69% |
| 46 | 10/27/1985 buf 17 @ phi (-9) 21 | 74.18% | 49.17% | 28.76% | 1.69% | 100.00% | 100.00% | 1.69% |
| 47 | 1/4/1981 dal 30 @ atl (-2.5) 27 | 57.15% | 77.00% | 79.97% | 98.24% | 0.00% | 0.00% | 1.76% |
| 48 | 9/12/1982 was 37 @ phi (-6.5) 34 | 68.03% | 89.22% | 59.07% | 98.24% | 50.00% | 0.00% | 1.76% |
| 49 | 11/19/2000 sdg 37 @ den (-9.5) 38 | 75.33% | 63.43% | 17.29% | 1.76% | 100.00% | 100.00% | 1.76% |
| 50 | 12/10/1995 sea 31 @ den (-7) 27 | 69.31% | 89.79% | 98.16% | 95.46% | 0.00% | 0.00% | 1.84% |
| 51 | 10/28/1984 den 22 @ rai (-6) 19 | 66.74% | 86.94% | 82.05% | 98.16% | 50.00% | 0.00% | 1.84% |
| 52 | 9/10/2000 rai 38 @ clt (-6.5) 31 | 68.03% | 94.19% | 98.05% | 21.96% | 0.00% | 0.00% | 1.95% |
| 53 | 11/12/2006 sdg 49 @ cin (1.5) 41 | 45.69% | 95.10% | 98.05% | 91.70% | 0.00% | 0.00% | 1.95% |
| 54 | 9/28/1980 nor 16 @ mia (-7) 21 | 69.31% | 66.89% | 28.76% | 2.01% | 100.00% | 100.00% | 2.01% |
| 55 | 10/21/1984 pit 16 @ clt (5) 17 | 35.92% | 28.71% | 5.71% | 2.01% | 100.00% | 100.00% | 2.01% |
| 56 | 9/13/1987 ram 16 @ oti (5) 20 | 35.92% | 20.85% | 10.14% | 2.01% | 100.00% | 100.00% | 2.01% |
| 57 | 11/26/1989 ram 20 @ nor (0) 17 | 50.00% | 71.99% | 76.22% | 97.80% | 50.00% | 0.00% | 2.20% |
| 58 | 9/20/1992 cin 23 @ gnb (0) 24 | 50.00% | 50.00% | 23.78% | 2.20% | 100.00% | 100.00% | 2.20% |
| 59 | 11/3/1996 cin 24 @ rav (-3.5) 21 | 59.96% | 78.85% | 97.79% | 95.63% | 0.00% | 0.00% | 2.21% |
| 60 | 9/16/1990 crd 23 @ phi (-13.5) 21 | 83.48% | 97.77% | 91.94% | 93.23% | 0.00% | 0.00% | 2.23% |
| 61 | 11/12/1978 oti 26 @ nwe (-7) 23 | 69.31% | 82.55% | 97.65% | 93.91% | 0.00% | 0.00% | 2.35% |
| 62 | 10/5/1980 buf 26 @ sdg (-7) 24 | 69.31% | 77.93% | 80.68% | 97.61% | 0.00% | 0.00% | 2.39% |
| 63 | 11/9/1980 kan 31 @ sea (-3) 30 | 58.56% | 47.51% | 94.29% | 97.61% | 0.00% | 0.00% | 2.39% |
| 64 | 10/6/1991 phi 13 @ tam (3) 14 | 41.44% | 42.57% | 43.93% | 2.39% | 100.00% | 100.00% | 2.39% |
| 65 | 11/1/1992 oti 20 @ pit (3) 21 | 41.44% | 33.11% | 47.97% | 2.39% | 100.00% | 100.00% | 2.39% |
| 66 | 9/19/1993 cle 19 @ rai (-3) 16 | 58.56% | 84.61% | 93.02% | 97.61% | 0.00% | 0.00% | 2.39% |
| 67 | 9/29/1996 ram 28 @ crd (-1) 31 | 52.87% | 30.14% | 25.39% | 2.39% | 50.00% | 100.00% | 2.39% |
| 68 | 12/29/2002 sea 31 @ sdg (-3) 28 | 58.56% | 34.63% | 67.67% | 97.61% | 50.00% | 0.00% | 2.39% |
| 69 | 12/11/1983 crd 34 @ rai (-9) 24 | 74.18% | 97.60% | 80.68% | 45.70% | 0.00% | 0.00% | 2.40% |
| 70 | 9/5/1983 dal 31 @ was (1.5) 30 | 45.69% | 77.00% | 97.51% | 79.09% | 0.00% | 0.00% | 2.49% |
| 71 | 9/17/1989 nor 34 @ gnb (4.5) 35 | 37.28% | 7.40% | 2.49% | 27.64% | 100.00% | 100.00% | 2.49% |
| 72 | 11/27/2005 ram 33 @ htx (3.5) 27 | 40.04% | 64.21% | 97.51% | 97.06% | 50.00% | 0.00% | 2.49% |
| 73 | 12/26/2010 htx 23 @ den (2.5) 24 | 42.85% | 23.00% | 3.15% | 2.49% | 100.00% | 100.00% | 2.49% |
| 74 | 10/2/2011 det 34 @ dal (-2.5) 30 | 57.15% | 77.00% | 96.85% | 97.51% | 0.00% | 0.00% | 2.49% |
| 75 | 12/11/1989 sfo 30 @ ram (2) 27 | 44.27% | 90.15% | 72.95% | 97.40% | 0.00% | 0.00% | 2.60% |
| 76 | 9/10/1995 clt 27 @ nyj (2) 24 | 44.27% | 85.09% | 90.74% | 97.40% | 50.00% | 0.00% | 2.60% |
| 77 | 11/26/1995 nwe 35 @ buf (-6) 25 | 66.74% | 64.60% | 88.93% | 97.40% | 0.00% | 0.00% | 2.60% |
| 78 | 12/30/2002 sfo 20 @ ram (-2) 31 | 55.73% | 45.03% | 5.15% | 2.60% | 100.00% | 100.00% | 2.60% |
| 79 | 11/20/1983 det 23 @ gnb (-4) 20 | 61.35% | 71.99% | 97.36% | 87.52% | 50.00% | 0.00% | 2.64% |
| 80 | 11/21/2010 buf 49 @ cin (-4) 31 | 61.35% | 59.86% | 97.36% | 71.76% | 0.00% | 0.00% | 2.64% |
| 81 | 12/8/1991 buf 30 @ rai (-1.5) 27 | 54.31% | 63.43% | 75.42% | 97.29% | 50.00% | 0.00% | 2.71% |
| 82 | 10/31/1999 nyg 23 @ phi (2.5) 17 | 42.85% | 43.80% | 90.31% | 97.29% | 50.00% | 0.00% | 2.71% |
| 83 | 12/14/1997 sea 22 @ rai (-1.5) 21 | 54.31% | 89.60% | 97.20% | 91.14% | 0.00% | 0.00% | 2.80% |
| 84 | 9/19/1999 clt 28 @ nwe (-4.5) 31 | 62.72% | 18.82% | 2.80% | 3.19% | 100.00% | 100.00% | 2.80% |
| 85 | 10/1/1989 atl 21 @ gnb (-7) 23 | 69.31% | 44.21% | 32.33% | 2.83% | 100.00% | 100.00% | 2.83% |
| 86 | 10/6/1991 min 20 @ det (-3) 24 | 58.56% | 34.63% | 16.65% | 2.83% | 100.00% | 100.00% | 2.83% |
| 87 | 12/15/1991 mia 30 @ sdg (1) 38 | 47.13% | 37.75% | 47.97% | 2.83% | 100.00% | 100.00% | 2.83% |
| 88 | 10/25/1981 kan 28 @ rai (-3) 17 | 58.56% | 77.93% | 97.03% | 93.91% | 0.00% | 0.00% | 2.97% |
| 89 | 12/1/1986 nyg 21 @ sfo (-3) 17 | 58.56% | 66.89% | 97.03% | 32.00% | 0.00% | 0.00% | 2.97% |
| 90 | 11/8/1992 cin 31 @ chi (-9) 28 | 74.18% | 71.29% | 97.03% | 90.85% | 50.00% | 0.00% | 2.97% |
| 91 | 10/14/2001 mia 17 @ nyj (3) 21 | 41.44% | 22.07% | 2.97% | 29.47% | 100.00% | 100.00% | 2.97% |
| 92 | 9/25/2011 det 26 @ min (3) 23 | 41.44% | 62.25% | 97.03% | 90.85% | 50.00% | 0.00% | 2.97% |
| 93 | 11/29/1981 rai 32 @ sea (0) 31 | 50.00% | 50.00% | 76.22% | 96.93% | 0.00% | 0.00% | 3.07% |
| 94 | 12/21/1986 was 21 @ phi (4) 14 | 38.65% | 82.01% | 88.93% | 96.93% | 0.00% | 0.00% | 3.07% |
| 95 | 10/13/1991 rai 23 @ sea (-2.5) 20 | 57.15% | 65.76% | 96.85% | 93.69% | 50.00% | 0.00% | 3.15% |
| 96 | 11/13/1994 min 20 @ nwe (2.5) 26 | 42.85% | 16.15% | 3.15% | 6.31% | 50.00% | 100.00% | 3.15% |
| 97 | 12/27/1997 min 23 @ nyg (-4.5) 22 | 62.72% | 78.24% | 96.85% | 92.75% | 0.00% | 0.00% | 3.15% |
| 98 | 11/4/2001 cle 21 @ chi (-4.5) 27 | 62.72% | 38.14% | 59.07% | 3.19% | 50.00% | 100.00% | 3.19% |
| 99 | 10/5/2003 rai 21 @ chi (3.5) 24 | 40.04% | 23.64% | 4.39% | 3.19% | 100.00% | 100.00% | 3.19% |
| 100 | 10/26/1980 pit 26 @ cle (3) 27 | 41.44% | 15.39% | 22.24% | 3.32% | 100.00% | 100.00% | 3.32% |
(“Comeback” lists the lowest probability that the winning team had at the end of any quarter.)
And just for fun, here’s a table of QBs since ’78 who led a comeback team in attempts during the game in question, ranked by the sum of their career “comeback points” (100% minus the comeback scores listed above):